News

Microsoft Releases Windows 10 Version 21H1 for 'Prerelease Validation'

• By Kurt Mackie
• March 18, 2021

Version 21H1 of Windows 10 isn't officially out yet, but Microsoft is making a prerelease version of it available to organizations for testing.

Windows 10 version 21H1 is currently ready for "commercial prerelease validation," according to an announcement Thursday by Aria Carley, a program manager on the Windows team. This release apparently is more polished than a Windows Insider Program test release. It's available through standard, non-Windows Insider Program outlets, "including Windows Update, Windows Server Update Services (WSUS), and Azure Marketplace, or you can download an ISO file," the announcement noted. 

In past explanations of Microsoft's Windows 10 channel releases (formerly known as "branch" releases), such an announcement might have been signaling a "semiannual channel targeted" release. Such a release was a prompt to IT pros to test the new OS in production environments with designated groups of users. These so-called testing "rings" were to check the new OS prior to a general rollout across the organization, according to Microsoft's scheme.

Microsoft dropped the "targeted" lingo a couple of years ago with the release of Windows 10 version 1903. Its old language is still around, though, Microsoft noted in this document:

Due to naming changes, older terms like CB [current branch] and CBB [current branch for business] might still be displayed in some of our products, such as in Group Policy. If you encounter these terms, "CB" refers to the Semi-Annual Channel (Targeted)--which is no longer used--while "CBB" refers to the Semi-Annual Channel.

After years of explaining the meaning of its branch/channel model language, Microsoft seems to have given up. This release is probably the now unnamed semiannual channel targeted release, which IT pros are supposed to deploy to testing rings.

The Windows 10 channels are now more broadly constituted. Presently, there are three channels:

• Semiannual channel, where OS feature updates arrive twice per year.
• Long-term servicing channel, with infrequent OS feature updates.
• Windows Insider Program, with various test OS releases.

It's not clear when that reformulation happened, but it's described in this "Overview" document, dated Feb. 17, 2021.

The new Windows 10 version 21H1 operating system won't be bringing many new features. Microsoft mentioned that aspect last month with the Windows Insider Program beta channel release. However, Microsoft did note that the new OS is bringing a fast installation experience for organizations already using Windows 10 versions 2004 or 20H2.

The fast installation happens because of Microsoft uses so-called "enablement packages," where the OS bits are already present on machines, but remain in a dormant state until activated. The use of enablement packages with the Windows 10 version 21H1 release was confirmed by Carley.